1. The Field of the Invention
The present invention relates to systems and methods for pulsing a high impedance load. More particularly, the present invention relates to systems and methods for compensating the rise times and ringing or overshoot responses associated with pulsed high impedance loads.
2. Background and Relevant Art
Pulse generators are devices that are used, for example, to generate an energy pulse that is delivered or applied to a load. Pulse generators deliver an energy pulse to loads such as, for example, spectrometers, accelerators, radar transmitters, high impedance electron guns, klystrons, as well as other equipment that require high voltage pulses. In this type of equipment, the energy pulses generated by the pulse generators should be fast and powerful.
In order to reduce the voltages actually generated by the pulse generators, pulse transformers are used to deliver the energy pulse the loads. The pulse transformers have a turn ratio that can provide the voltages required by the load. In many situations, the voltage delivered to the load can be quite large. For example, a pulse transformer may be used to deliver a voltage on the order of 30 kV (kilovolt) to 100 kV. Typical high impedance loads range from 1500 ohms to 30 kilohms.
One problem associated with delivering a pulse to a high impedance load through a pulse transformer is that significant ringing may result in the waveform. The ringing is partially associated with the rise time. When a fast rise time is needed, the target voltage of the pulse is often overshot and ringing results as the circuitry attempts to compensate. In other words, high impedance loads that are driven through a pulse transformer often experience ringing when trying to achieve fast rise times.
Another reason that makes it difficult to shorten rise times and reduce ringing is related to stray capacitance associated with the load. Stray capacitance adversely affects the rise time of the pulse on the load. As the stray capacitance increases, the rise time increases. The impedance of the load in combination with the stray capacitance can thus affect the ability of a pulse transformer based system to generate pulses that have a sufficiently fast rise time and minimal ringing.